GOLD MINING IN COLOEADO. 515 



showing an excellent seam of ore. The mine lias been worked almost alto- 

 gether by underhand stoping, and nearly all the ground known to be produc- 

 tive has been taken out. The shafts are now being sunk in the hope of get- 

 ting ground opened in advance of the demands of the mill. The manager 

 and captain of the mine are experienced men in their business, and appreciate 

 the advantages of regular and systematic mining, but when money is needed 

 and must be produced by the mine, the ore must be taken out with less regard 

 for economy in the future than for the pressing necessities of the present. 



During 1867 the mine was worked very profitably, as will be seen further 

 on, but the production was stopped almost entirely in January, 1868, by the 

 breaking down of the pump. Previous to that time the water, of which there 

 was and is a great deal, was removed by a small and overworked pump that 

 finally gave out entirely and suffered the mine to fill up with water. During 

 the first half of 1868, the principal work done was to obtain and put in place 

 a new and efficient pump. This was accomplished in August of that year. The 

 pump is the largest and most costly of any in the Territory. It is established in 

 the central shaft and consists of two 14-inch plungers, or force-pumps, one at 220 

 feet, the other at 440 feet below the surface. A draw-lift pump is attached 

 below the second plunger. The column is 15 inches in diameter, and is made 

 of riveted iron plate, one-fourth of an inch thick, like those in use in Cali- 

 fornia and Nevada. The pipe of the column is made in sections 15 feet long, 

 with a stout cast flange at each end, by which they may be connected together. 

 The working-rod is an 8-inch square timber, in sections about 30 feet long, 

 joined by splice similar to that shown in Fig. 6, Plate IX. 



The shaft, which is sunk vertically to a depth of 220 feet, inclines at that 

 point at an angle of 86°. In order to accommodate the pump-rod to this change 

 in direction, the continuation of if is clanaped to the vertical part in manner shown 

 in the figure. The main or vertical rod passes through guides below the joint 

 in order to prevent vibration and to counteract the lateral force exerted by the 

 inclined portion of the rod. 



The pump runs on a five-foot stroke and makes five strokes per minute. 

 It is operated by means of a "bob" and driving-wheel at the surface in the 

 usual way, but the power is transmitted to the pumping-gear from the engine 

 at the eastern shaft, which is between 100 and 150 feet distant, by means of 



